1. Field Of The Invention
The invention generally relates to cable manufacturing machinery, and more specifically to a bobbin sorting apparatus for collecting bobbins having different specified wires and dispensing them in a desired order or sequence for further processing, such as by cabling machines or group twinners.
2. Description Of The Prior Art
Communication cables are composite cables typically formed of many twisted wire pairs each of which may have its own specified physical and electrical properties. Thus, wire pairs may differ in the gauges of the wires, the pitch at which the wires are twisted and the coded colors of the insulations of the wires so that they can be readily identified by those that install or service the cables. In North America, for example, a typical long distance communication cable may include 25 twisted pairs although in Europe 10 twisted pair cables are more common. Thus, for example, as many as 50 color selections may be required during the assembly of the cable, some colors of which may be duplicated or repeated in different wire pairs. Bobbins of a particular color, gauge, etc. are normally stored in the same rack compartments at a storage or input location. If there are 25 color codes, the rack may have 25 different compartments. Such compartments may be located either along a single horizontal level or may be stored in multiple vertical columns Ten different colors may, therefore, be stored in two vertical racks of 5 compartments or bins aligned in vertical columns above each other.
The process of twinning which forms the individual twisted pairs has typically been an independent one which is performed after the differently colored insulating layers have been extruded onto the wires, but before stranding of all of the individual wire pairs using double twist machines. While the lays of the twisted pairs can be controlled by regulating the speeds of rotations of the individual double twist machines, the other aspects of the twisted pairs including the selections of wire gauges and insulation colors has presented considerable difficulties. Normally, the bobbins wound with different wires having different gauge sizes and color insulations are maintained in storage racks which are continually supplied with such bobbins, frequently from an extruding station which is located upstream of the line. As the bobbins are wound with wire having specified properties, they are transferred to the storage bins, from which they must be selectively delivered to the gang or group twinners for the twinning and subsequent stranding operations. Gang or group twinners for manufacturing communication cables are produced by various companies. Such twinners may be ganged in any number of units. In order to decrease down time and maximize the efficiency of the twinning operations, it is extremely important to use a reel handling system which can quickly and easily select bobbins having the desired wire characteristics from the storage bins and deliver them to the appropriate twinners so that the proper twisted pairs can be made. Numerous loading systems of this type have been proposed, ranging from fully robotic to manual systems.
In some common installations, the units are fed from a floor conveyor system which moves the reels to the correct positions for loading. The conveyor is fed either manually or from an existing material handling system. Manual procedures can be automated by means of programmed packages which utilize computers in conjunction with the conveyer systems.
While sophisticated approaches have been proposed for collecting different bobbins from storage bins and loading them onto specified twinners, the proposed solutions continue to suffer serious disadvantages and are normally not cost effective.
In one proposed system, a fully automatic robot take-up is programmed to travel along tracks between the various storage bins and the individual twinners. The robot is programmed to remove a reel from a storage bin and place it at a desired location, such as a storage shelf, reel carriage or on the floor beside the twinning machine. However, the robot moving speed is approximately 30 meters per minute, and the robot lifting speed is approximately 10 meters per minute. Since the robot is designed to select and transport only one bobbin at a time, it is clear that the operation of replacing many bobbins can be extremely slow. Any delays in the bobbin sorting and transfer operations, of course, translate into increased down time for the machines and a drop in efficiency in terms of product output A system of the type aforementioned is sold by Nokia of Helsinki, Finland and the system is described in Catalog No. 11.00 published in 1976. A somewhat similar system is disclosed in U.S. Pat. No. 4,610,404, which discloses a robot device for the loading of empty spools and unloading of full spools into and from winding machines aligned in a single file on one side of a track. A carriage is provided which moves along the track and stops at the machine to be served. However, the robot device, again, is designed to replace only one bobbin at a time and this renders the robot device inefficient.
In U.S. Pat. No. 4,076,132, a bobbin transporting and storage system is disclosed which is intended to move loaded bobbins from extruders to storage racks. Bobbins having wires of similar characteristics are loaded onto chutes and simultaneously ejected onto an appropriate storage rack intended for those bobbins. The bobbins, however, are individually manually removed at the outlet ends of the storage racks and placed on a conveyer for further processing. The manual operation of removing individual bobbins from the racks is, as with the previously discussed systems, slow and reduces the efficiency of the line.
In U.S. Pat. No. 4,071,150, a system is disclosed for supplying conductors for a communication capable making apparatus. Here, bobbins are manually arranged on storage racks each slated to receive a particular wire pair. Twenty-five such storage racks are arranged in each of four horizontal rows stacked one above the other, and an elevator is used to simultaneously remove 25 bobbins from each row. The elevator brings the bobbins to the ground level and ejects them onto a conveyer at which time all 25 bobbins are removed to a stranding station. The bobbins, therefore, are pre-arranged on the individual racks and there is no selectivity during removal of the bobbins since all 25 bobbins in one row are simultaneously deposited onto the elevator, and the order in which they are placed on the elevator is the same order in which they are conveyed once ejected.
In U.S. Pat. No. 4,655,665, there is described a bobbin magazine used in conjunction with a yarn processing machine. The magazine is in the nature of a vertical conveyer which supports compartment-defining elements secured to the conveyer band. The magazine is manually loaded with stacks of fresh bobbin tubes and a door is provided to the enclosure which houses the conveyer which can be opened to provide access to the various compartments to insert a stick of tubes. All of the tubes are generally identical and there is no sorting involved, the advantage of the device being that there is substantially a doubling of a number of compartments within a given length of conveyer, since the compartments are formed on both sides of the conveyer. Since all of the bobbin tubes are essentially identical, there is no requirement for reversal of the conveyer drive direction in order to more quickly access specified compartments to be loaded with specific bobbins.
The prior art systems have failed to provide the flexibility or versatility of rapid random selection or arrangement of bobbins on storage racks or removal of bobbins from such racks for arrangement of a predetermined number of bobbins having specified electrical and/or other characteristics in a desired order or sequence.